High-performance electrolyte for molten carbonate fuel cell

ABSTRACT

A motive machine can be selectively operable in a plurality of functional modes. The motive machine can include a drive wheel a steering assembly (610), and a controller (604). The drive wheel can be rotatably secured to a body of the motive machine. The steering assembly (610) can be operable to steer the motive machine. The controller (604) can be in communication with a steering sensor (606), a steering motor, and a limit sensor (608, where the controller (604) can be configured to synchronize the steering motor to the steering sensor (606) as a function of a limit signal.

TECHNICAL FIELD

This application claims the benefit of priority to U.S. patent application Ser. No. 15/628,295, filed on Jun. 20, 2017, which is herein incorporated by reference herein in its entirety.

TECHNICAL FIELD

This document pertains generally, but not by way of limitation, to controlling a machine, such as a motive machine that can be a hybrid machine having both fuel-powered and battery-powered modes. More specifically, the disclosure can be applied to an industrial floor cleaning machine, such as a hybrid sweeper-scrubber machine. However, aspects of the disclosure can be applied to machines other than hybrid machines and machines other than industrial floor cleaning machines.

BACKGROUND

Hybrid machines that use both fuel-powered modes (e.g., gas engines) and battery-powered modes have been introduced to replace machines that previously were solely fuel-powered machines. Control modules can be used to control the function of the machine and to switch between the fuel-powered and electric powered modes. One area where hybrid machines have been introduced is in floor cleaning machines.

Industrial and commercial floors can be cleaned on a regular basis for aesthetic and sanitary purposes. There are many types of industrial and commercial floors ranging from hard surfaces, such as concrete, terrazzo, wood, and the like, which can be found in factories, schools, hospitals, and the like, to softer surfaces, such as carpeted floors found in restaurants and offices. Different types of floor cleaning equipment, such as scrubbers, sweepers, and extractors, have been developed to properly clean and maintain these different floor surfaces.

A typical scrubber is a walk-behind or drivable, self-propelled, wet process machine that applies a liquid cleaning solution from an onboard cleaning solution tank onto the floor through nozzles fixed to a forward portion of the scrubber. Rotating brushes forming part of the scrubber rearward of the nozzles agitate the solution to loosen dirt and grime adhering to the floor. The dirt and grime become suspended in the solution, which is collected by a vacuum squeegee fixed to a rearward portion of the scrubber and deposited into an onboard recovery tank.

Scrubbers are very effective for cleaning hard surfaces. Unfortunately, debris on the floor can clog the vacuum squeegee, and thus, the floor should be swept prior to using the scrubber. Thus, sweepers are commonly used to sweep a floor prior to using a scrubber. A typical sweeper is a self-propelled, walk-behind, or drivable dry process machine which picks debris off a hard or soft floor surface without the use of liquids. The typical sweeper has rotating brushes which sweep debris into a hopper or “catch bin.” Combination sweeper-scrubbers have been developed that provide the sweeping and scrubbing functionality in a single unit.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which are not necessarily drawn to scale, like numerals can describe similar components in different views. Like numerals having different letter suffixes can represent different instances of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various examples discussed in the present document.

FIG. 1 is a top perspective view of an illustrative hybrid sweeper-scrubber that can utilize a scrub deck retraction apparatus, in accordance with at least one example.

FIG. 2 is a bottom perspective view of the hybrid sweeper-scrubber of FIG. 1, in accordance with at least one example.

FIG. 3 is an internal perspective of the hybrid sweeper-scrubber of FIG. 1, in accordance with at least one example.

FIG. 4 is a flow chart illustrating an illustrative control method that can be used with a machine such as, but not limited to, the hybrid sweeper-scrubber of FIG. 1, in accordance with at least one example.

FIG. 5 is an illustrative schematic diagram of various components of a control method that can be used with a machine such as, but not limited to, the hybrid sweeper-scrubber of FIG. 1, in accordance with at least one example.

FIG. 6 is an illustrative schematic diagram of various components of a control system that can be used with a machine such as, but not limited to, the hybrid sweeper-scrubber of FIGS. 1-5, in accordance with at least one example.

FIG. 7 is an isometric view of a portion of a steering assembly of the hybrid sweeper-scrubber of FIGS. 1-6, in accordance with at least one example.

FIGS. 8A and 8B are charts representing some functions of the steering assembly of the hybrid sweeper-scrubber of FIGS. 1-6, in accordance with at least one example.

FIG. 9A is an illustrative schematic diagram of various components of a steering system that can be used with a machine such as, but not limited to, the hybrid sweeper-scrubber of FIGS. 1-8, in accordance with at least one example.

FIG. 9B is a chart representing some functions of the steering assembly of the hybrid sweeper-scrubber of FIGS. 1-9A, in accordance with at least one example.

FIG. 10 is an isometric view of a portion of a steering assembly of the hybrid sweeper-scrubber of FIGS. 1-9A, in accordance with at least one example.

FIG. 11A is a top isometric view of a portion of a steering assembly of the hybrid sweeper-scrubber of FIGS. 1-10, in accordance with at least one example.

FIG. 11B is a top view of a portion of a steering assembly of the hybrid sweeper-scrubber of FIGS. 1-10, in accordance with at least one example.

FIG. 12 is a cross section view of a portion of a steering assembly across section 12-12 of FIG. 7, in accordance with at least one example.

FIGS. 13A and 13B illustrate a focused portion of the cross-sectional view of a portion of a steering assembly of FIG. 12 in two conditions, in accordance with at least one example.

FIGS. 14A and 14B are flow charts illustrating an illustrative control method that can be used with a machine such as, but not limited to, the hybrid sweeper-scrubber of FIGS. 1-13, in accordance with at least one example.

FIG. 15 is a flow chart illustrating an illustrative control method that can be used with a machine such as, but not limited to, the hybrid sweeper-scrubber of FIGS. 1-13, in accordance with at least one example.

DETAILED DESCRIPTION

The present disclosure relates generally to machines, such as motive machines that have a movable or transport aspect. In some examples, the machine can be a hybrid machine that may be operated in a fuel-powered or battery-powered mode. However, this disclosure includes features that can be applied to machines that do not necessarily have a hybrid power system (e.g., fuel only or electric only).

In some examples, the machine can include a cleaning apparatus such as a sweeper-scrubber. For the purposes of illustration, a hybrid sweeper-scrubber machine is described herein. Again, the disclosure may be applied to other types of machines, including other types of vehicles and machines that do not have a cleaning aspect.

Conventional machines such as motive machines can have steering system related challenges. One challenge related to drive-by-wire steering systems is that they lack the same feel to the user as a mechanical steering system that users are accustomed to. The mechanical systems naturally provide more of a tactile feedback as the resistance changes with turning of the wheel. Drive-by-wire systems do not naturally have the same feel as the mechanical systems that users are used to. The inventors have recognized, among other things, that a torque feedback system can be attached to a shaft of a steering wheel to provide torque feedback to a user.

Cleaning machines can be subject to other steering challenges as well. For example, cleaning machines have an additional challenge of providing controlled application of a cleaning solution, especially during sharp turns when more cleaning solution can be dispensed than when the machine is traveling in a straight line. Further, dispensing more solution than needed can cause a secondary issue of applying more solution than can be completely recovered, leaving an undesirable amount of solution behind. The inventors have recognized, among other things, that a controller can adjust a dispenser or a speed of the sweeper-scrubber to adjust an amount of fluid or solution dispensed around corners. In some examples, the amount of fluid can be dispensed based on a steering angle of the drive wheel.

Hybrid Sweeper-Scrubber Overview

One illustrative but non-limiting example of the hybrid sweeper-scrubber of the present invention is illustrated in FIGS. 1 and 2. An illustrative schematic diagram of the hybrid sweeper-scrubber components is illustrated in FIG. 3. The sweeper-scrubber of FIGS. 1-3 provides all of the functionality of a prior art sweeper-scrubber system through the use of electric components, although hydraulics can be used to operate the hopper for debris collection.

The present control method and system for the hybrid sweeper-scrubber can include an internal combustion engine and electrical system battery pack to power the hybrid sweeper-scrubber and operate a number of accessories and cleaning functions. The present control method and system can include common components between the engine and electrical systems. Benefits of such examples can include reduced material costs, reduced component maintenance, reduced overall size of the hybrid sweeper-scrubber, elimination of a number of hydraulic components, lower emissions, or less fuel consumption.

FIGS. 1 and 2 are top and bottom perspective views, respectively, of an example of a sweeper-scrubber 30 that can utilize a scrub brush retraction apparatus in accordance with the present patent application. As illustrated in FIGS. 1 and 2, the sweeper-scrubber 30 can include a sweeper system 32 for sweeping a floor surface and a scrubber system 34 for scrubbing the floor surface. Thus, as will be discussed in further detail below, the sweeper-scrubber 30 can be operable to sweep dirt and debris from the floor surface, spray a liquid cleaning solution from an onboard cleaning solution tank onto the floor being cleaned, and agitate the cleaning solution. Suction means can then be used to draw the cleaning solution into an onboard recovery tank.

Providing a floor cleaning system having both a sweeper system 32 and a scrubber system 34 can allow the operator to perform both “dry” and “wet” cleaning with the same system. These sweeping and scrubbing modes can be operated either separately or simultaneously depending upon the type of cleaning required.

As further illustrated in FIGS. 1 and 2, the sweeper-scrubber 30 can include a chassis 36 supporting a machine body 37 and having a forward end 38 and a rearward end 40 joined by sides 42. The chassis 36 can be supported by one or more floor engaging front wheels 44 and one or more rear steerable wheels 46. The one or more rear steerable wheels 46 can be operatively connected to a steering wheel 48 through the chassis 36. Alternatively, the chassis can be supported by one or more front steerable wheels and one or more floor engaging rear wheels. The steering wheel can be part of a steering control system (e.g., 566, FIG. 5) as described herein.

A driver seat 50 can be supported by the machine body 37 rearward of the steering wheel 48 for use by an operator of the sweeper-scrubber 30. The operator can sit on the driver seat 50 to operate the steering wheel 48 and foot operated control pedals 52, such as a brake and an accelerator, supported above a chassis top surface 54 The accelerator can be included in a speed control system (e.g., 564, FIG. 5), as described herein.

Cleaning Operation

In operation, a spray nozzle can spray a liquid cleaning solution from an onboard cleaning solution tank onto the floor being cleaned. The cleaning solution can be gravity fed through the spray nozzle, or alternatively pumped out of the cleaning solution tank through the spray nozzle. The spray nozzle can be integrated into a scrub sub-system (e.g., 578, FIG. 5), as described herein. The cleaning solution sprayed onto the floor can then be agitated by one or more ground engaging scrub brushes, such as scrub brushes 56A, 56B, and 56C. In an example, the scrub brushes 56A-56C together form a portion of a scrub deck assembly 59 of the scrubber system 34 adjacent to a bottom surface of the chassis 36. As illustrated in FIGS. 1 and 2, the outside scrub brush 56A and an associated skirt 57A can protrude from the side of the sweeper-scrubber 30 to improve scrubbing close to walls and other obstacles. As will be discussed in detail below, the outside scrub brush 56A can be attached to a pivoting arm that can allow the scrub brush 56A and the adjacent side skirt 57A to swing around a vertical axis, such that it can travel rearward and/or inward, to retract under the machine and prevent damage to the scrub deck assembly 59 caused by hitting obstacles. The scrub brushes 56A, 56B, 56C and associated components can be part of a sweep subsystem (e.g., 576, FIG. 5), as described herein.

As illustrated in FIGS. 1 and 2, the ground engaging scrub brushes 56A-56C can have substantially parallel axes of rotation that are generally perpendicular to the floor surface. The scrub brushes 56A-56C can be rotatably driven by a suitable motor, and can be configured to agitate the cleaning solution sprayed onto the floor surface to dislodge dirt and grime adhered thereto. In addition to the scrub brushes 56A-56C, the scrubber system 34 can further include a floor engaging vacuum squeegee assembly 58 positioned proximal the chassis rearward end 40. The agitated cleaning solution and suspended dirt and grime can be drawn off the floor surface through the squeegee assembly 58 and into the recovery tank for disposal, such as with a recovery sub-system (580, FIG. 5), as described herein.

The squeegee assembly 58 can be coupled to a squeegee support bracket 60 pivotally attached relative to the chassis 36, and can be moved between an operating position and a stored position (when not in use). The squeegee assembly 58, which can be operable to dry the floor being cleaned by the sweeper-scrubber 30, can include a forward arcuate squeegee blade 62 nested within a rearward arcuate squeegee blade 64. In an example, the nested squeegee blades 62 and 64 can extend substantially across the width of the sweeper-scrubber 30 and can define a crescent shaped vacuum zone 66. The squeegee blades 62 and 64 can be formed from any flexible material that can sealingly engage the floor, including elastomeric materials such as rubber, plastic, or the like.

The forward squeegee blade 62 can be configured to collect the cleaning solution on the floor, and can include notches in its floor engaging edge which allows the cleaning solution to enter the vacuum zone 66. The rearward squeegee blade 64 can include a continuous floor engaging edge in order to prevent the escape of the cleaning solution rearwardly from the vacuum zone 66.

As illustrated in FIGS. 1 and 2, a pair of side brushes 68 can be rotatably mounted proximal the chassis forward end 38 and forward of the ground engaging agitation brushes 56. The side brushes 68 can be driven by a suitable motor controlled by control circuitry. Each side brush 68 can be rotatable about a substantially vertical axis proximal one of the chassis sides 42, and can be configured to urge debris towards a centerline of the chassis 36 for pick-up by a main sweeper brush 69. In an example, the main sweeper brush 69 can be rotatable about a substantially horizontal axis. As illustrated in FIGS. 1 and 2, each side brush 68 can extend radially from its vertical axis past one side 42 of the chassis 36 in order to sweep the floor along a wall or other vertical or angled surface. Similar to the squeegee assembly 58, the side brushes 68 can be vertically movable between an operating position and a storage position.

Hybrid Sweeper-Scruber: Internal Components

FIG. 3 is an internal perspective of the hybrid sweeper-scrubber 30 of FIG. 1, the internal components shown as 300. As illustrated in FIG. 3, the hybrid sweeper-scrubber includes an internal combustion engine 352 that drives an electrical system alternator 354 via a suitable belt. The internal combustion engine 352 can include a number of combustible fuels including, but not limited to, diesel, natural gas, propane, ethanol, petroleum, and the like. The electrical system alternator 354 can be configured so as to start the engine and system of the hybrid sweeper-scrubber. In an example, the electrical system alternator can include a 42V alternator and regulator. The electrical system alternator 354 charges an electrical system battery pack 356 and is operably coupled to a main controller 362, a speed controller (not shown) (e.g., FIG. 5, 564), and a steering controller (not shown) (e.g., FIG. 5, 566). The electrical system alternator can provide enough power so as to start the engine 352 of the hybrid sweeper-scrubber. The hybrid sweeper-scrubber can alternate between a number of running modes of the self-propelled hybrid vehicle, including at least an electric running mode and a hybrid running mode, the hybrid mode include running the engine on a combustible fuel and powering a number of cleaning functions (e.g., sub-systems) via the electrical system batter pack or electrical system alternator.

In an example, the electrical system battery pack 356 can include a number of 36V batteries. The main controller 362, speed controller, and steering controller are also coupled to the electrical system battery pack 352. The hybrid sweeper-scrubber can provide steering such as a wire steering system. A traction drive motor/system may be controlled by the speed controller. As described herein, engine speed can be controlled through the main controller, so as to adjust the engine operation to account for whichever cleaning functions are operating.

Control Method 430

Now that an example of a floor cleaning system has been described that can utilize the control method of the present patent application, the method and structure of an illustrative control method 430 will be described in detail with reference to FIGS. 4-5.

FIG. 4 illustrates of an example of a control method 430 of the hybrid sweeper-scrubber of FIG. 1. At 432, power can be provided, via an electrical system alternator (e.g., 354, FIG. 3), to at least one cleaning function of a self-propelled hybrid vehicle. A cleaning function can include a number of accessories or sub-systems, as described herein in connection with FIGS. 1-3 and 5. Accessories can include a head light, signal lights, break lights, a horn, and the like.

At 434, an operational load can be monitored, including an operational state of the at least one cleaning function of the self-propelled hybrid vehicle. Operational load can include an engine power output threshold for the at least one cleaning functional to be operational. Operational state can include on/off or a percentage of full operational speed, power, torque, and the like.

Running State of Engine

At 436, a running state of the internal combustion engine (e.g., 352, FIG. 3) can be controlled based on the monitored operational load, so as to adjust the running speed of the internal combustion engine to a distinct running speed, so as to at least produce the monitored operational load. In an example, the running speed can be altered according to a number cleaning functions with an active operation state, so as to dictate an engine power output threshold for the at least one cleaning function to be in the active state. The running speed can be increased to provide greater power output than the monitored operational load due to a number of additional environmental impacts on the load, so as to provide enough power for the at least one cleaning function to remain in an active operational state. Environmental impacts can include, but are not limited to, inclined or declined surfaces, surface types (e.g., smooth, rough, uneven, etc.), or ambient temperature.

Running Speed of the Engine

The running speed can include an idle speed, so as to provide power output sufficient to charge the electrical system battery pack or operate an operational accessory. A threshold engine speed can be maintained for a number of cleaning functions to operate during a manual adjustment of the running speed of the engine, such as by an operator of the hybrid sweeper-scrubber. For example, the operator is able to increase and decrease the engine speed at will, but the main controller will not allow the engine to run slower than a power output needed for the operational cleaning functions.

Regulating Engine Speed

In some examples, the control method and control system can regulate engine speed or revolutions per minute (RPM) at a number of settings based on the number of operational cleaning functions, such as by monitoring the active cleaning functions that are in operation. The RPMs can be set at distinct values. For example, if only the sweep sub-system (e.g., 376, FIG. 5) is operational then a lower sweep RPM setting (RPM Setting #1) of the engine can be activated, such as about 1700 RPM to about 2500 RPM. However, if both the sweep sub-system and scrub sub-system (e.g., 378, FIG. 5) are being operated then a RPM setting (RPM Setting #2) higher than the lower sweep RPM setting on the engine can be activated, such as greater than about 2700 RPM.

The control method and system can regulate the engine speed based on a number of modes, including but not limited to: optional high pressure washer option can cause the engine to run at a lower RPM mode (RPM Setting #1); if the engine is in idle (RPM Setting Idle), the engine will can run at a lower RPM mode (RPM Setting #1) when sweeping only or vacuuming only; if the engine is in idle or run, the engine can run in a higher RPM mode (RPM Setting #2) when scrubbing only or scrubbing and sweeping; if an operator override is activated, the operator can change between a higher RPM mode (RPM Setting #2) and a lower RPM mode (RPM Setting #1) at the operator's discretion; or, if the operator override condition goes away (e.g. sweep sub-system turns off) and the operator has not changed the engine mode, the engine can be returned to the mode before the forced override.

Threshold Charge

At 438, a threshold charge can be maintained, via the electrical system alternator (e.g., 154, FIG. 3), of the electrical system battery pack (e.g., 156, FIG. 3). For example, the amount of voltage stored in the electrical system battery pack can be maintained or optimized while the engine is running or the hybrid sweeper-scrubber is operational.

Electric Mode Fault

The electric mode can include monitoring the electrical system alternator for an occurrence of an electrical component fault, such as a voltage below a threshold voltage or an indication of a belt failure. The electrical system alternator can be monitored per a set time interval or continuously. Protective measures can be taken if the occurrence of an electrical component fault is detected, such as providing a warning to an operator, shutting down the self-propelled hybrid vehicle, or the like.

Hybrid Mode Fault

The hybrid mode can include monitoring the self-propelled hybrid vehicle for an occurrence of an engine component fault, such as the engine runs out of fuel, if the engine fails, if the engine generator fails, if the belt from the engine to engine alternator fails, etc. The running mode can be shifted to the electric mode if the occurrence of an engine component fault is detected. As described herein, the running mode can be altered by an operator if an override mode is activated.

If the machine is operating from the electrical system battery pack only, such as due to a failure in the engine or engine alternator as discussed herein or by operator override, the control system can monitor battery voltage of the electrical system battery pack until a threshold voltage condition is met. At such point, the control system can protect the hybrid sweeper-scrubber by shutting off machine cleaning functions and shutting down the hybrid sweeper-scrubber.

Electrical System Schematic & Sub-Systems

FIG. 5 illustrates an illustrative schematic diagram 550 of various electrical components 310 for the hybrid sweeper-scrubber of FIGS. 1-3. Like numerals in FIGS. 3 and 5 can represent like components. For example, internal combustion engine 352 in FIG. 3 corresponds to the electrical aspect of the engine shown as engine system 552 in FIG. 5.

The internal combustion engine 552 can be operably coupled to an electrical system alternator 554, such as via a belt 553. The electrical system alternator 554 can be configured to charge an electrical system battery pack 556 and operably coupled to a number of controllers 562, 564, 566. In an example the electrical system alternator 554 can be operably coupled to or through a fuse box 560. The number of controllers 562, 564, 566 can be operably coupled to the electrical system battery pack 556. Controller 564 can include a speed controller operably coupled to a drive system 570, so as to control the speed of the hybrid sweeper-scrubber. Controller 566 can include a steering control operably coupled to a steering system 572, so as to steer or provide directional capabilities to the hybrid sweeper-scrubber. Controller 562 can include a machine main controller (MMC) configured to control a running state of the internal combustion engine 552 of the self-propelled hybrid vehicle based on a monitored operational load. The main controller 562 can be operably coupled to any of a user interface 568, an accessory, or a number of sub-systems 576, 578, 580, 582, directly or indirectly. The user interface 568 can be configured so as to indicate a status of a sub-system, a measurement, an alarm, a time, or the like. The MMC 562 can be configured to monitor the electrical system alternator 554 to detect failures, as described herein.

The sub-systems can include any of a sweep sub-system 576, a scrub sub-system 578, or a recovery sub-system 580, as described herein. Further, the control method and system can include an engine system 552, such as an engine controller controlled by the MCM 362 or a computer processing unit associate with control logic for operation of the engine 552 (e.g., engine 352, FIG. 3).

An engine alternator 558 can be operably coupled to an engine battery 360, so as to start the internal combustion engine 552, as described herein.

A switching component can also be provided that can be configured to alternate the self-propelled hybrid vehicle between a number of running modes, the number of running modes including at least an electric mode and a hybrid mode, as described herein. A running state override switching component can be configured to override an operator initiated running state if the operator running initiated state is below a threshold run state based on the monitored operational load, as described herein.

In an example, the hybrid sweeper-scrubber can include a regenerative braking method or system to improve fuel efficiency, such as providing charge to the electrical system battery pack. The hybrid sweeper-scrubber control method and system can include a data acquisition system, so as to provide a number of measurements used in charge algorithms, running speed algorithms, failure mode detections, and the like.

Control System Overview

FIG. 6 is an illustrative schematic diagram of various components of system 600 that can be used with a machine such as, but not limited to, the hybrid sweeper-scrubber of FIGS. 1-5, in accordance with at least one example.

System 600 can include main controller (MMC) 602, steering module 604, steering sensor 606, limit sensor 608, steering assembly 610, pedal 612, wheel drive module 614, fluid dispenser 618, fluid collector 620, battery cells 622, relay 624, relay 626, and wheel drive contactor 628.

MMC 602, steering module 604, and wheel drive module 614 can each be controllers, controller modules, computers, direct digital controllers, programmable logic controllers, or other microelectronic processing systems configured to send and receive signals and perform operations based on data and signals, any of which can include machine readable medium. The terms “machine readable medium” may include any medium that is capable of storing, encoding, or carrying instructions for execution by the device and that cause the device to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding or carrying data structures used by or associated with such instructions. Non-limiting machine readable medium examples may include solid-state memories, and optical and magnetic media. Specific examples of machine readable media may include: non-volatile memory, such as semiconductor memory devices (e.g., Electrically Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks.

Sensor 606 can be a steering sensor configured to produce a steering signal as a function of sensed rotation. In some examples, sensor 606 can be a rotary Hall Effect sensor, and can be an optical sensor in other examples. In some examples, sensor 606 can include a feedback device, as discussed in further detail below. Limit sensor 608 can be a limit switch configured to produce a limit signal as a function of a detected limit of rotation of a steering component, as discussed below in further detail. Limit sensor 608 can be a position sensor, such as a magnetic reed switch, but can be other proximity or position sensors (such as various contact and optical sensors), in other examples.

Steering assembly 610 can be an assembly configured to drive and steer a motive machine or a sweeper-scrubber (such as sweeper-scrubber 30 of FIG. 1). As discussed further below, steering assembly 610 can include a drive motor, steering motor, drive wheel, and steering drive. Pedal 612 can be an electronic throttle control device configured to control the amount of power provided by the driver motor to the drive wheel to thereby control a speed of the motive machine or sweeper-scrubber. Pedal 612 can be various types of variable voltage signal generators, such as a potentiometer, and the like.

Fluid dispenser 618 can be a spray nozzle configured to spray a liquid cleaning solution or fluid from an onboard cleaning solution tank onto a floor. The cleaning solution or fluid can be gravity fed through nozzles in some examples and can alternatively be pumped out of the cleaning solution tank through the spray nozzle or nozzles in other examples. In some examples, the spray nozzle or nozzles can be integrated into a scrub sub-system. Fluid collector 620 can be an assembly including a squeegee and a vacuum, in some examples, configured to collect fluid or solution from the floor.

Battery cells 622 can be batteries configured to store power. In some examples, battery cells 622 can be connected to and can receive power from an engine and/or an alternator. Relay 624 and relay 626, and contactor 628 can be electrically operated switches configured to transfer power between lines.

MMC 602 can be operably connected to fluid dispenser 618, fluid collector 620, battery cells 622 (though not shown in FIG. 6), relay 624, wheel drive module 614, and steering module 604. Steering module 626 can be further connected to relay 626, steering sensor 606, limit switch 608, steering assembly 610, and wheel drive module 614. Wheel drive module 614 can be further connected to battery cell 622, relay 624, pedal 612, relay 628, and steering assembly 610.

In operation of some examples, battery cells 622 can distribute power to the other components of system 600, where controller 602, steering module 604, and wheel drive module 614 can determine when power is to be distributed using relays and contactors to connect and distribute power as required. Once system 600 is started and is running, pedal 612 can provide a power signal to wheel drive module 614, which can control contactor 628 to selectively allow power to be delivered to the driver motor of steering assembly 610 to power the drive wheel of steering assembly 610, moving motive machine or the scrubber sweeper.

As the motive machine moves, its direction can be controlled using a steering wheel connected to a steering sensor. The position of the wheel can be detected by the sensor and transmitted to steering module 604. Steering module 604 can analyze the signal and transmit an appropriate signal in response to a steering motor of steering system 610 to effectively turn the drive wheel, causing the motive machine to turn in the direction the steering wheel is turned. As indicated in FIG. 6, temperature information can be returned from steering system 610 to steering module 604 and driver module 614, which steering module 604 and driver module 614 can monitor to prevent overheating or other problems of the driving motor and steering motor. Encoding feedback can also be sent to steering module 604 and driver module 614 from steering assembly 610 to ensure precise driving of and turning of the drive wheel. Feedback from travel limit sensors or switches can also be provided to steering module 604 to help monitor the steering angle and synchronize steering sensor 606 to the steering motor, as discussed below in detail.

Though multiple controllers (MMC 602, steering module 604 and driver module 614) are shown, a single controller can be used in some examples. Alternatively, more controllers can be used in other examples.

Steering System

FIG. 7 is an isometric view of a portion of steering assembly 700 of the hybrid sweeper-scrubber of FIGS. 1-6, in accordance with at least one example. Steering assembly 700 can include steering wheel 702, steering shaft 704, steering sensor 706, and shaft joint 708 (which can include a cover).

Steering wheel 702 can be a rigid wheel coupleable to steering shaft 704. Steering shaft 704 can be a rigid shaft comprised of metals, plastics, composites, combinations thereof, and the like. Steering shaft can be coupled to shaft joint 708, which can be a U-joint in some examples, and can be surrounded by a cover (as shown in FIG. 7). Steering sensor 706 can be coupled to a distal portion of steering shaft 704, opposite steering wheel 702. Steering sensor 706 can be a steering sensor configured to produce a steering signal as a function of sensed rotation of steering shaft 704 therein. Steering sensor 706 can operate to transmit the steering signal to steering module 604. In some examples, steering sensor 706 can be a rotary Hall Effect sensor, and can be an optical sensor in other examples. In some examples, steering sensor 706 can include a torque feedback device to provide feedback to steering wheel 702 and therefore to the operator, as discussed in further detail below in FIGS. 12 and 13.

FIGS. 8A and 8B are charts representing some functions of the steering assembly of the hybrid sweeper-scrubber of FIGS. 1-6, in accordance with at least one example. FIG. 8A illustrates graph 800A, which can be a representation of a direct current (DC) simulated three phase power transmission to an alternating current (AC) motor, such as the steering motor of the sweeper-scrubber, using square waves, which can be produced using a DC to AC inverter, in some examples. In some examples a variable frequency drive, variable speed drive, or pulse width modulation (PWM) controller can provide the square wave power to the steering motor to control a speed at which the steering motor operates. Graph 800A can include first phase 802, second phase 804, and third phase 806, which can all be square waves, or simulated sinusoidal waves generated by quickly switching power on and off.

Graph 800B illustrates sinusoidal power waves, first phase A, second phase B. and third phase C, which can be provided to the steering motor (such as steering motor 1006, discussed below) from an AC source. Use of sinusoidal waves with an AC motor can provide a higher torque to power ratio than DC square waves, but can complicate timing control of the motor, thus complicating control of the steering system. In one solution to this problem, a commutator resolver can be used, as described below, to address the timing issues.

FIG. 9A is an illustrative schematic diagram of various components of a steering system that can be used with a machine such as, but not limited to, the hybrid sweeper-scrubber of FIGS. 1-8, in accordance with at least one example. FIG. 9B is a chart representing some functions of the steering assembly of the hybrid sweeper-scrubber of FIGS. 1-9A, in accordance with at least one example.

FIG. 9A shows commutator resolver 900A, which can include magnet 902 that can be placed on a rotor of the steering motor. Magnet 902 can include south pole 908 and north pole 910. Commutator resolver 900A can also include Hall Effect sensors (or generator coils) 904 and 906. Coil 904 can include Sin A and Sin B terminals and coil 906 can include Cos A and Cos B terminals. As the rotor of the steering motor spins, so too does magnet 902, which can generate a signal unique to the position of the magnet allowing steering module 604 (which can receive the signal) to determine a position of the rotor and therefore the timing of the power phases required to maintain operation. An example of the resulting output signal is shown in FIG. 9B as Sin and Cos curves. The signals can be transmitted to the drive controller (such as steering module 604), which can be used to synchronize the power transmitted to the steering motor.

FIG. 10 is an isometric view of a portion of steering and drive assembly 1000 of the hybrid sweeper-scrubber of FIGS. 1-9A, in accordance with at least one example. Assembly 1000 can include drive motor 1002, body or frame 1004, steering motor 1006, drive wheel 1008, and steering drive 1010.

Body or frame 1004 can be a rigid member secured to a chassis or body of a scrubber-sweeper or motive machine, and can be comprised of rigid materials such as metals, plastics, combinations thereof, and the like. Drive motor 1002 can be a three phase AC motor secured to body 1004, coupled to drive wheel 1008 to transmit rotation thereto, and controlled via pedal 612 and drive module 614, as discussed above. Steering motor 1006 can be a three phase AC motor coupled to steering drive 1010 and can be secured to body 1004. Steering motor 1006 can be communicably coupled to steering module 604, in some examples. Drive wheel 1008 can be rotatably coupled to body 1004 and can be mechanically coupled to steering motor. Drive motor 1002 can be engaged with drive wheel 1008 (through a hub or linkage system, for example) to transmit rotation thereto.

In operation of some examples, power can be controllably transmitted to drive motor 1002. In response, drive motor 1002 can produce a rotational output that is transmitted to drive wheel 1008, which can thereby rotate to drive or move the sweeper-scrubber. When it is desired to turn the sweeper-scrubber, an operator can rotate steering wheel 702, which can rotate steering shaft 704 (both of FIG. 7). As steering shaft 704 (of FIG. 7) is rotated, steering sensor 706 can detect the rotation and transmit a signal to steering module 604 (of FIG. 6). Steering module 604 can output a pulse width modulated (PWM) signal to steering motor 1006 to rotate drive wheel 1008. In response, steering motor 1006 can transmit electrical power to rotation of a shaft coupled to steering drive 1010, thereby transmitting rotation to steering drive 1010. As steering drive 1010 is rotated about its central axis by steering motor 1006, drive wheel 1008 can rotate as well.

FIG. 11A is a top isometric view of a portion of steering assembly 1000 of the hybrid sweeper-scrubber of FIGS. 1-10, in accordance with at least one example. FIG. 11B is a top view of a portion of steering assembly 1000 of the hybrid sweeper-scrubber of FIGS. 1-10, in accordance with at least one example. FIGS. 11A and 11B are discussed below concurrently. The components of steering assembly 1000 as shown in FIGS. 11A and 11B can be consistent with those of FIG. 10; however, FIGS. 11A and 11B show further details and operations of steering assembly 1000. For example, steering assembly 1000, can include drive motor 1002, steering drive 1010, first limit switch 1012, and second limit switch 1014. First limit switch 1012 and second limit switch 1014 can be consistent with limit switch 608 of FIG. 6 above, in some examples.

FIG. 11B illustrates drive wheel 1008 in multiple position to illustrate operation of limit switches 1012 and 1014. Drive wheel 1008 is illustrated in a left maximum position 1008L where steering drive 1010 (which can include a magnet to activate limit switch 1012 or a portion of limit switch 1012) can activate limit switch 1012. Limit switch 1012 can then transmit a left or first limit signal to steering module 604, for example. Similarly, FIG. 11B also illustrates drive wheel 1008 in a right maximum position 1008R where steering drive 1010 can activate limit switch 1014, which can then transmit a right or second limit signal to steering module 604, for example. Each limit signal can indicate to steering module 604 that drive wheel 1008 is at angle θ (at a right maximum) or −θ (at a left maximum; −θ not shown). This positional data can be correlated to an angle of steering shaft 704, which can be used to synchronize steering shaft 704 to drive wheel 1008. The positional data can also be used to determine when drive wheel 1008 is in a zero position or home position, as indicated by drive wheel 1008.

FIG. 12 is a cross section view of a portion of a steering assembly across section 12-12 of FIG. 7, in accordance with at least one example. Torque feedback device (TFD) 1200 can include (among other parts not visible), inner shaft 1202, fluid 1204, and outer housing 1206. Inner shaft 1202 can be a rigid shaft coupled to steering shaft 704 of FIG. 7, in some examples. Outer housing 1206 can be a rigid housing coupled to (or secured within) steering sensor 706 (of FIG. 7). In some examples, outer housing can be secured to a rigid portion of the sweeper-scrubber such that inner shaft 1202 is rotatable relative to outer shaft 1206. Fluid 1204 can be a magnetorheological fluid that is electrically controlled. In some examples, MR Fluid can be a suspension of small particles that can be configured to align in the presence of a magnetic field. The magnetic field can align the particles, modifying the viscosity of the MR fluid, to the point that fluid 1204 can become rigid with an elastic-like sheer strength, thereby resisting sheer forces applied thereto by inner shaft 1202 and outer housing 1206.

In operation of some examples, when steering module 604 detects that a rotational limit has been reach (from either of limit sensors 1212 and 1214), steering module 604 can adjust the magnetic field of TFD to create a resistance in the steering shaft, indicating to the operator that a steering limit has been reached, which can help the operator effectively and efficiently steer the scrubber-sweeper. In another example, once a position of drive wheel 1008 is synchronized to a rotational position of steering shaft 704, an adjustment to the MR fluid can be made proportionally to the steering angle or drive wheel angle.

FIGS. 13A and 13B illustrate focused portion 13 of the cross-sectional view of a portion of a steering assembly of FIG. 12, in accordance with at least one example. 13A and 13B can be consistent with the FIGS. above; however, FIG. 13A illustrates TFD 1300A in a first condition and FIG. 13B illustrates TFD 1300B in a second condition. In both FIGS. 13A and 13B. TFD 1300 can include (among other parts not visible), inner shaft 1202, fluid 1204, and outer housing 1206, as described above with respect to FIG. 12. However, FIGS. 13A and 13B show how fluid 1204 can change with the application of a magnetic field to fluid 1204.

TFD 1300A shows particles 1208 as randomly placed between inner shaft 1202 and outer housing 1206 when no or little magnetic field is applied to fluid 1204. In this configuration, the RM fluid may not apply feedback (may not resist shear forces or torques) to inner shaft 1202 (or the steering shaft). Alternatively, TFD 1300B shows particles 1208 of fluid 1204 as aligned when a magnetic or electromagnetic field is applied to fluid 1204. In this configuration, fluid 1204 (MR fluid) can be aligned by the magnetic field applied by steering sensor 706. The alignment of particles 1208 can increase the viscosity of fluid 1204 (MR fluid), making fluid 1204 somewhat rigid with an elastic-like sheer strength. This can provide a torque feedback through steering wheel 702 to an operator by increasing resistance required to turn steering wheel 702 in the same direction. This can increase steering efficiency and control. In some examples, the electromagnetic field can be removed if inner shaft 1202 is turned in the opposite direction, as detected by steering sensor 706 and determined by steering module 604.

Example Methods of Operation

FIG. 14A is a flow chart illustrating a control method that can be used with a machine such as, but not limited to, the hybrid sweeper-scrubber of FIGS. 1-13, in accordance with at least one example of this disclosure. Method 1400 can include steps to automatically synchronize steering of a steering wheel of a motive machine (or sweeper-scrubber) to rotation of a drive wheel to improve steering and handling of the motive machine. The steps or operations of method 1400 (and of each method discussed herein) are illustrated in a particular order for convenience and clarity; many of the discussed operations can be performed in a different sequence or in parallel without materially impacting other operations. Method 1400 as discussed includes operations performed by multiple different actors, devices, and/or systems. It is understood that subsets of the operations discussed in method 1400 attributable to a single actor, device, or system could be considered a separate standalone process or method.

At step 1402, method 1400 can begin after startup and can determine whether a shipping mode has been enabled. If the shipping mode is activated, method 1400B can be performed (as described below). If the shipping mode is not activated, step 1404 can be performed, a steering signal can be produced by steering sensor 706 as a function of a position of a steering wheel shaft 704. In some examples of method 1400A, step 1404 may not be performed. The steering signal can be delivered to steering controller or module 604, as described above, and can be used to drive steering motor 1006 to rotate steering drive 1010 at step 1406. Alternatively, at step 1406, steering module 604 can instruct steering motor 1006 to rotate steering drive 1010 to a maximum. Then, at step 1408, a limit signal can be produced by one or more of limit sensors 1012 and 1014 as a function of rotation of steering drive 1010 to a maximum rotation to activate the limit sensor. As step 1410, the steering motor can be synchronized to the steering sensor based on the limit signal, and the steering signal produced by steering sensor 706.

Alternatively, method 1400A can be performed by turning drive wheel 1008 to both maximum directions, where method 1400 can further include the step of manually or automatically driving steering drive 1010 to a first maximum to produce a first limit signal at step 1414 and driving steering drive 1010 to a second maximum to produce a second limit signal at step 1416. The two maximum positions can be used to determine the location of a zero position or home position drive wheel 1008 at step 1418. In some examples, stored positional data or location information of the position of the first limit sensor and the second limit sensor relative to each other, the drive wheel, and the steering drive can be used at step 1420 to more accurately determine the zero position of the drive wheel at step 1418. Thereafter, at step 1410 the determined home position of the drive wheel can be used to synchronize steering sensor 706 to steering motor 1006 as a function of one or more of the first limit signal, the second limit signal, the zero position of the motor, and the stored positional information.

FIG. 14B is a flow chart illustrating a control method that can be used with a machine such as, but not limited to, the hybrid sweeper-scrubber of FIGS. 1-13, in accordance with at least one example of this disclosure. Method 1400B can be used when it is determined at step 1402 of method 1400A that shipping mode has been activated. The shipping mode prevents the automatic homing or zeroing sequence of method 1400B from being performed. Instead, homing or zeroing of the drive wheel and synchronization between the steering sensor and steering motor can be performed as the motive machine or scrubber-sweeper is operated. Disabling this sequence can help prevent damage to the drive wheel caused by turning the wheel into shipping constraints or blocks comprised of rigid materials (such as wood) of a shipping pallet or container.

Method 1400B can begin at step 1404, where a steering signal can be produced by steering sensor 706 as a function of a position of a steering wheel shaft 704, which can be manually operated by an operator. The steering signal can be delivered to steering controller or module 604, as described above, and can be used to drive steering motor 1006 to rotate steering drive 1010 at step 1406. At step 1408, a limit signal can be produced by one or more of limit sensors 1012 and 1014 as a function of rotation of steering drive 1010 to a maximum rotation to activate the limit sensor. Then, at step 1410, steering motor 1006 can be synchronized to the steering sensor based on one or more of the limit signal and the steering signal produced by steering sensor 706 by determining a home or zero position of drive wheel 1008 using the signal(s).

Method 1400 can further include the step of driving steering drive 1010 to a first maximum to produce a first limit signal at step 1414 and driving steering drive 1010 to a second maximum to produce a second limit signal at step 1416. The two maximum positions can be used to determine the location of a zero position or home position drive wheel 1008 at step 1418. In some examples, stored positional data or location information of the position of the first limit sensor and the second limit sensor relative to each other, the drive wheel, and the steering drive can be used at step 1420 to more accurately determine the zero position of the drive wheel at step 1418. Thereafter, at step 1410 the determined home position of the drive wheel can be used to synchronize steering sensor 706 to steering motor 1006 as a function of one or more of the first limit signal, the second limit signal, the zero position of the motor, and the stored positional information.

FIG. 15 is a flow chart illustrating control method 1500 that can be used with a machine such as, but not limited to, the hybrid sweeper-scrubber of FIGS. 1-13, in accordance with at least one example of the present disclosure. Method 1500 can be in addition to or concurrent with method 1400 as discussed further below. Method 1500 can further provide operations to variably discharge or dispense a fluid or solution from the sweeper-scrubber to minimize wet spots on the floor that may occur especially at turning points. Similarly a recovering rate can also be varied.

Method 1500 can begin at step 1502, where drive wheel 1008, which can be rotatably secured to a body of the motive machine, can be driven by drive motor 1002. At step 1504 a steering wheel can be operated or rotated to produce a steering signal from steering sensor 706 as function of rotation of measured rotation of steering shaft 704. At step 1506 the steering signal can be transmitted to steering motor 1006 to rotate drive wheel 1008 as a function of the steering signal. At step 1508, a one or more limit signals can be produced (in some examples according to steps 1414 and 1416 of method 1400) as a function of a position of the steering drive. At step 1510, a steering angle can be determined as a function of the limit signal or signals and the steering signal so that the steering motor or steering drive 1010 can be synchronized to steering sensor 706 at step 1512.

Then, at step 1514, a fluid or solution can be variably dispensed from the motive machine to a ground surface as a function of the steering angle. In some examples, because the steering angle can be known anywhere between the zero position and the maximum position, fluid can be dispensed proportionally at step 1520 to an absolute value of the steering angle. This can help reduce a volume of fluid dispensed in turns, which can help to reduce wet spots and conserve solution. At step 1516, fluid or solution dispensed by the fluid dispenser can be recovered using a vacuum system of the motive machine. In some examples, at step 1522, a rate of recovery (or a vacuum rate) can also be varied as a function of the steering angle. In one example, as steering angle increases and solution dispensing decreases, an adjustment can be made to the PWM input voltage to the vacuum motors, which can reduce vacuum speed and therefore can reduce airflow and water lift, saving energy. In another example, vacuum speeds can be increased to help to collect additional fluid applied at turns to further reduce wet spots.

At step 1518 a speed of the motive machine or sweeper scrubber can be adjusted as a function of the steering angle. This can be used to more precisely control movement of the sweeper-scrubber, particularly around corners. This can also be used, where, in some examples, the speed of the motive machine directly controls a volume of fluid or solution dispensed. In this way, by adjusting a speed of the motive machine as a function of the steering angle, solution dispensing can be controlled as a function of steering angle to reduce wet spots.

Various Notes and Examples

To better illustrate the devices and methods disclosed herein, a non-limiting list of examples is provided herein.

Example 1 is a motive machine selectively operable in a plurality of functional modes, the motive machine comprising: a drive wheel rotatably secured to a body of the motive machine; a steering assembly operable to steer the motive machine, the steering assembly comprising: a steering wheel operable to steer the drive wheel, the steering wheel including a steering shaft; a steering sensor coupled to the steering shaft to produce a steering signal as a function of sensed rotation of the steering shaft; a steering drive coupled to the drive wheel and rotatable with the drive wheel; a steering motor operably engaged with the steering drive to rotate the steering drive and drive wheel; and a limit sensor engaged with the steering drive to produce a limit signal as a function of rotation of the steering drive to a maximum rotation; and a controller in communication with the steering sensor, the steering motor, and the limit sensor, the controller configured to synchronize the steering motor to the steering sensor as a function of the limit signal.

In Example 2, the subject matter of Example 1 optionally includes wherein the limit sensor further comprises a first limit sensor and a second limit sensor, each of the first limit sensor and second limit sensor engaged with the steering drive, the first limit sensor configured to produce a limit signal as a function of rotation of the steering drive to a left maximum rotation and the second limit sensor configured to produce a limit signal as a function of rotation of the steering drive to a right maximum rotation.

In Example 3, the subject matter of Example 2 optionally includes wherein the first limit sensor and the second limit sensor are reed sensors.

In Example 4, the subject matter of any one or more of Examples 2-3 optionally include wherein the controller is configured to receive the first limit signal and the second limit signal and synchronize the steering sensor with the steering motor as a function of the first limit signal and the second limit signal.

In Example 5, the subject matter of any one or more of Examples 2-4 optionally include wherein, at startup of the motive machine, the controller is configured to drive the steering motor to rotate the steering drive in a first direction until the first limit sensor is engaged by the steering drive and produces the first limit signal and is configured to drive the steering motor to rotate the steering drive in a second direction until the second limit sensor is engaged by the steering drive and produces the second limit signal.

In Example 6, the subject matter of any one or more of Examples 1-5 optionally include the steering assembly further comprising: a torque feedback device coupled to the steering shaft, the torque feedback device in communication with the controller and configured to apply a torque to the shaft as a function of the steering signal.

In Example 7, the subject matter of Example 6 optionally includes the wherein the torque feedback device further comprises: a first collar coupled to the steering shaft; a second collar coupled to the body; and a magnetorheological fluid disposed between the first collar and the second collar, the magnetorheological fluid responsive to the steering signal.

Example 8 is a motive machine selectively operable in a plurality of functional modes, the motive machine comprising: a drive wheel rotatably secured to a body of the motive machine; a steering wheel operable to steer the drive wheel, the steering wheel including a steering shaft; a steering sensor coupled to the steering shaft to produce a steering signal as a function of sensed rotation of the steering shaft; a fluid dispenser secured to the body and configured to variably dispense a fluid from the motive machine to a ground surface; and a controller in communication with the steering sensor, the steering motor, and the fluid dispenser, the controller configured to determine a steering angle as a function of the steering sensor and configured to operate the fluid dispenser to variably dispense the fluid as a function of the steering angle.

In Example 9, the subject matter of Example 8 optionally includes wherein: the fluid dispenser is configured to variably dispense the fluid from the motive machine as a function of a speed of the motive machine, and wherein the controller is configured to adjust the speed of the motive machine as a function of steering angle to adjust fluid output.

In Example 10, the subject matter of Example 9 optionally includes a drive motor coupled to the drive wheel to impel the drive wheel, the controller in communication with the drive motor to control the speed of the motive machine as a function of the steering angle.

In Example 11, the subject matter of any one or more of Examples 8-10 optionally include a vacuum system secured to the body and configured to recover fluid dispensed by the fluid dispenser, wherein the controller is configured to vary a vacuum speed as a function of the steering angle.

In Example 12, the subject matter of any one or more of Examples 8-11 optionally include wherein a flow rate of the dispensed fluid is proportional to steering angle such that the flow rate of fluid dispensed is reduced as the steering angle increases and is increased as the steering angle decreases.

Example 13 is a method of operating a multi-function motive machine, the method comprising: producing a steering signal as a function of a position of a steering wheel shaft; rotating a steering drive as a function of the steering signal using a steering motor that drives a steering drive; producing a limit signal as a function of rotation of the steering drive to a maximum rotation; and synchronizing the steering motor to the steering sensor as a function of the limit signal.

In Example 14, the subject matter of Example 13 optionally includes driving the steering drive to a first maximum to produce a first limit signal; driving the steering drive to a second maximum to produce a second limit signal; and determining a zero position of the drive wheel as a function of the first limit signal and the second limit signal.

In Example 15, the subject matter of any one or more of Examples 13-14 optionally include determining the zero position of the drive wheel as a function of the first limit signal, the second limit signal, and stored positional data of at least one of a first limit sensor, a second limit sensor, and the steering drive.

In Example 16, the subject matter of any one or more of Examples 13-15 optionally include synchronizing the steering sensor to the steering motor as a function of the first limit signal and the second limit signal.

In Example 17, the subject matter of any one or more of Examples 13-16 optionally include initializing a shipping mode to prevent the controller from automatically driving the steering drive to a maximum at startup.

Example 18 is a method of operating a multi-function motive machine, the method comprising: driving a drive wheel rotatably secured to a body of the motive machine using a drive motor; producing a steering signal as function of rotation of a steering shaft; transmitting the steering signal to a steering motor to rotate a drive wheel as a function of the steering signal; producing a limit signal as a function of a position of the steering drive; determining a steering angle as a function of the limit signal and the steering signal; and dispensing variably, a fluid from the motive machine to a ground surface as a function of the steering angle.

In Example 19, the subject matter of Example 18 optionally includes dispensing variably, the fluid from the motive machine as a function of a speed of the motive machine; adjusting the speed of the motive machine using the drive motor as a function of steering angle to adjust fluid output.

In Example 20, the subject matter of any one or more of Examples 18-19 optionally include recovering fluid dispensed by the fluid dispenser using a vacuum system of the motive machine; varying a vacuum rate as a function of the steering angle.

In Example 21, the subject matter of any one or more of Examples 18-20 optionally include dispensing fluid proportional to the steering angle such that a flow rate of fluid dispensed is reduced as the steering angle increases and the flow rate of fluid dispensed is increased as the steering angle decreases.

In Example 22, the device, assembly, or method of any one of or any combination of Examples 1-21 is optionally configured such that all elements or options recited are available to use or select from.

The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific examples in which the invention can be practiced. These examples are also referred to herein as “examples.” Such examples can include elements in addition to those shown or described. However, the present inventors also contemplate examples in which only those elements shown or described are provided. Moreover, the present inventors also contemplate examples using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein.

In the event of inconsistent usages between this document and any documents so incorporated by reference, the usage in this document controls.

In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. In this document, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other examples can be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to comply with 37 C.F.R § 1.72(b), to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed example. Thus, the following claims are hereby incorporated into the Detailed Description as examples or examples, with each claim standing on its own as a separate example, and it is contemplated that such examples can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. 

What is claimed is:
 1. A motive machine selectively operable in a plurality of functional modes, the motive machine comprising: a drive wheel rotatably secured to a body of the motive machine; a steering assembly operable to steer the motive machine, the steering assembly comprising: a steering wheel operable to steer the drive wheel, the steering wheel including a steering shaft; a steering sensor coupled to the steering shaft to produce a steering signal as a function of sensed rotation of the steering shaft; a steering drive coupled to the drive wheel and rotatable with the drive wheel; a steering motor operably engaged with the steering drive to rotate the steering drive and drive wheel; and a limit sensor engaged with the steering drive to produce a limit signal as a function of rotation of the steering drive to a maximum rotation; and a controller in communication with the steering sensor, the steering motor, and the limit sensor, the controller configured to synchronize the steering motor to the steering sensor as a function of the limit signal.
 2. The motive machine of claim 1, wherein the limit sensor further comprises a first limit sensor and a second limit sensor, each of the first limit sensor and second limit sensor engaged with the steering drive, the first limit sensor configured to produce a limit signal as a function of rotation of the steering drive to a left maximum rotation and the second limit sensor configured to produce a limit signal as a function of rotation of the steering drive to a right maximum rotation.
 3. The motive machine of claim 2, wherein the first limit sensor and the second limit sensor are reed sensors.
 4. The motive machine of claim 2, wherein the controller is configured to receive the first limit signal and the second limit signal and synchronize the steering sensor with the steering motor as a function of the first limit signal and the second limit signal.
 5. The motive machine of claim 2, wherein, at startup of the motive machine, the controller is configured to drive the steering motor to rotate the steering drive in a first direction until the first limit sensor is engaged by the steering drive and produces the first limit signal and is configured to drive the steering motor to rotate the steering drive in a second direction until the second limit sensor is engaged by the steering drive and produces the second limit signal.
 6. The motive machine of claim 1, the steering assembly further comprising: a torque feedback device coupled to the steering shaft, the torque feedback device in communication with the controller and configured to apply a torque to the shaft as a function of the steering signal.
 7. The motive machine of claim 6, the wherein the torque feedback device further comprises: a first collar coupled to the steering shaft; a second collar coupled to the body; and a magnetorheological fluid disposed between the first collar and the second collar, the magnetorheological fluid responsive to the steering signal.
 8. A motive machine selectively operable in a plurality of functional modes, the motive machine comprising: a drive wheel rotatably secured to a body of the motive machine; a steering wheel operable to steer the drive wheel, the steering wheel including a steering shaft; a steering sensor coupled to the steering shaft to produce a steering signal as a function of sensed rotation of the steering shaft; a fluid dispenser secured to the body and configured to variably dispense a fluid from the motive machine to a ground surface; and a controller in communication with the steering sensor, the steering motor, and the fluid dispenser, the controller configured to determine a steering angle as a function of the steering sensor and configured to operate the fluid dispenser to variably dispense the fluid as a function of the steering angle.
 9. The motive machine of claim 8, wherein: the fluid dispenser is configured to variably dispense the fluid from the motive machine as a function of a speed of the motive machine, and wherein the controller is configured to adjust the speed of the motive machine as a function of steering angle to adjust fluid output.
 10. The motive machine of claim 9, further comprising: a drive motor coupled to the drive wheel to impel the drive wheel, the controller in communication with the drive motor to control the speed of the motive machine as a function of the steering angle.
 11. The motive machine of claim 8, further comprising: a vacuum system secured to the body and configured to recover fluid dispensed by the fluid dispenser, wherein the controller is configured to vary a vacuum speed as a function of the steering angle.
 12. The motive machine of claim 8, further comprising: wherein a flow rate of the dispensed fluid is proportional to steering angle such that the flow rate of fluid dispensed is reduced as the steering angle increases and is increased as the steering angle decreases.
 13. A method of operating a multi-function motive machine, the method comprising: producing a steering signal as a function of a position of a steering wheel shaft; rotating a steering drive as a function of the steering signal using a steering motor that drives a steering drive; producing a limit signal as a function of rotation of the steering drive to a maximum rotation; and synchronizing the steering motor to the steering sensor as a function of the limit signal.
 14. The method of claim 13, further comprising: driving the steering drive to a first maximum to produce a first limit signal; driving the steering drive to a second maximum to produce a second limit signal; and determining a zero position of the drive wheel as a function of the first limit signal and the second limit signal.
 15. The method of claim 13, further comprising: determining the zero position of the drive wheel as a function of the first limit signal, the second limit signal, and stored positional data of at least one of a first limit sensor, a second limit sensor, and the steering drive.
 16. The method of claim 13, further comprising: synchronizing the steering sensor to the steering motor as a function of the first limit signal and the second limit signal.
 17. The method of claim 13, further comprising: initializing a shipping mode to prevent the controller from automatically driving the steering drive to a maximum at startup.
 18. A method of operating a multi-function motive machine, the method comprising: driving a drive wheel rotatably secured to a body of the motive machine using a drive motor; producing a steering signal as function of rotation of a steering shaft; transmitting the steering signal to a steering motor to rotate a drive wheel as a function of the steering signal; producing a limit signal as a function of a position of the steering drive; determining a steering angle as a function of the limit signal and the steering signal; and dispensing variably, a fluid from the motive machine to a ground surface as a function of the steering angle.
 19. The method of claim 18, further comprising: dispensing variably, the fluid from the motive machine as a function of a speed of the motive machine; and adjusting the speed of the motive machine using the drive motor as a function of steering angle to adjust fluid output.
 20. The motive machine of claim 18, further comprising: recovering fluid dispensed by the fluid dispenser using a vacuum system of the motive machine; and varying a vacuum rate as a function of the steering angle.
 21. The motive machine of claim 18, further comprising: dispensing fluid proportional to the steering angle such that a flow rate of fluid dispensed is reduced as the steering angle increases and the flow rate of fluid dispensed is increased as the steering angle decreases. 